Enable built-in echo canceler if available.

1. Always initialize AudioRecord with VOICE_COMMUNICATION.
2. If echo canceler is available, disable our echo suppressor.

Change-Id: Idf18d3833189a8478c1b252ebe6ce55e923280b3
diff --git a/voip/jni/rtp/AudioGroup.cpp b/voip/jni/rtp/AudioGroup.cpp
index 64db250..c031eee 100644
--- a/voip/jni/rtp/AudioGroup.cpp
+++ b/voip/jni/rtp/AudioGroup.cpp
@@ -484,7 +484,7 @@
         ON_HOLD = 0,
         MUTED = 1,
         NORMAL = 2,
-        EC_ENABLED = 3,
+        ECHO_SUPPRESSION = 3,
         LAST_MODE = 3,
     };
 
@@ -619,6 +619,10 @@
     if (mode < 0 || mode > LAST_MODE) {
         return false;
     }
+    if (mode == ECHO_SUPPRESSION && AudioSystem::getParameters(
+        0, String8("ec_supported")) == "ec_supported=yes") {
+        mode = NORMAL;
+    }
     if (mMode == mode) {
         return true;
     }
@@ -775,8 +779,8 @@
     AudioTrack track;
     AudioRecord record;
     if (track.set(AudioSystem::VOICE_CALL, sampleRate, AudioSystem::PCM_16_BIT,
-        AudioSystem::CHANNEL_OUT_MONO, output) != NO_ERROR ||
-        record.set(AUDIO_SOURCE_MIC, sampleRate, AudioSystem::PCM_16_BIT,
+        AudioSystem::CHANNEL_OUT_MONO, output) != NO_ERROR || record.set(
+        AUDIO_SOURCE_VOICE_COMMUNICATION, sampleRate, AudioSystem::PCM_16_BIT,
         AudioSystem::CHANNEL_IN_MONO, input) != NO_ERROR) {
         LOGE("cannot initialize audio device");
         return false;